Edwin h



u'b.'"24,971. Patented May :6, I899. E. H. roman.-

ELEGTBIC MOTOR STARTING SWITCH.

(Application filed Jan. 19, 1899.)

(No Model.) 2 Sheets-Shut I.

WITNESSES: INVENTOR E.H;Parter W 51%;? m ATTOR EY v THE Noam ws'rcns co PHOTO L|TNO., WASHINGTON. u. c.

No. 624,97l. Patented May l6, I899. E. H. PORTER.

ELECTRIC MOTOR STARTING SWITCH.

(Application filed Jan. 19, 1899.) (No Model.) 2 Sheets-Sheet 2.

| l l l l IL WITNESSES:

UNITED STATES- PATENT OFFICE.

EDIVIN I-I. PORTER, OF FORT WAYNE, INDIANA.

ELECTRIC-M OTOR-STARTI NG SWITCH.

SPECIFICATION forming part of Letters Patent No. 624,971, dated May 16, 1899.

Application filed January 19, 1899. Serial No. 702,752. (No model) To a, whom it may concern:

Be it known that I, EDWIN I-I. PORTER, a citizen of the United States of America, and a resident of Fort \Vayne, in the county of Allen andState of Indiana, have invented a new and useful Improvement in Electric-Motor- Starting Switches, of which the following is a specification;

My present invention relates to an electricmotor-starting rheostat-switch so constructed as to be automatic in cutting out the motor from the circuit when the current is shut oif or when the motor is overloaded and also when both the field-current is off and the arm aturecurrent is too high.

In general the organization embodying my invention consists of two levers, means for interlockin g said levers together, a magnet in the main circuit, and a magnet in a shunt-circuit, the said magnets controlling the locking mechanism. One lever carries the main magnet and is adapted to connect the main terminal of the rheostat with the various terminals of the resistance-coils. The other lever has the shunt-magnet and handle, while both levers have retractile springs which tend to return the levers, respectively, to their normal positions. When the main magnet is sufficiently powerful, as it is when the current is abnormally strong, the two levers are released from each other and fly back to their normal olf position, thereby protecting the electric motor from what might be a serious injury, or if the current is cut off the shunt-magnet causes the release and the levers are returned by the retractile springs, and likewise, as before, the motor is cut out instantly.

Figure 1 is a plan of the device embodying my invention. The dotted lines represent parts which are hidden from view. Fig. 1 is a different view of the weighted catch for the core f. Fig. 2 is a side elevation of the same device. Fig. 3 is a diagram of the circuits of the device.

Referring to the drawings, a is one lever, and b is the other lever. Y

ais a retractile spring for the lever to, and b is a retractile spring for the lever 12, their object being to hold the levers apart from each other at an angle, as clearly represented in Fig. 1.

The lever b has a handle 0, so that it may be turned around the pivot d, which is common to the levers a and b. The lever a has no handle, but may be operated manually when interlocked with the lever b.

Inside of the handle 0 is a magnet e, of fine wire, for carrying a shunt-current from a constant-potential circuit. f is a coarse -wire magnet located inthe main or armature circuit of the motor. The lever a also carries contacts 9 and g, which are adapted to bear, respectively,npon the terminal h of the resistance-coils 1' and upon the various terminals j of said resistance-coils, so as to conductively connect them successively in'series or to cut them out similarly. Vhen the lever a,therefore, is moved back and forth, the resistancecoils may be cut in and out in the usual manner of operating rheostats.

The core 6 of the magnet c has a head 6 to act as a stop when the core 6 is drawn inwardly and to complete a magnetic circuit, holding it up as long as the current flows in the coil. Said core has also a slot 7o running longitudinally thereof. In the slot is a pin held movable in the slot and carried by one arm of the lever m, the other arm m being adapted to interlock with the arm n of a weighted lever, whose other arm is the ballweight n, said ball lying in the path of the core f of the magnetf and subject to magnetic attraction of the magnet f. When the current energizes the magnet e, the core 6 is drawn inwardly, by which action the lever a is adapted to be pushed along by and with the lever 12. On the other hand, too strong a current in the magnet f will throw the core f against the ball at and release the arms m and 71, both having engaging teeth to, so that the springs a and Z) will return the levers a and b to their normal off positions.

1) is the binding-post for the main line, and p is the armature binding-post, the former being connected to the first one of the contacts j and the latter being connected to the common terminal of the rheostat-coils, which latter is also connected to one terminal of the shuntmagnet 6, whose other terminal is connected to the small shunt binding-post q. The terminals of the series magnet f are connected to cross the two sets of rheostat-terminals,

and it is this magnet which forms the conductor between the terminals g and g, which are carried on the lever a.

From the above construction it follows that when the currentin the magnet f is stronger than a predetermined amount the levers a and b will be unlocked from each other and will be sprung back to their normal positions, and that also when the current in the magnet e is too Weak the levers a and Z) will be similarly operated regardless of the position they happen to be in on the face of the rheostat or on the series of contacts.

In the practical equipment of the device the instrument should be set up so that the le vers a and I) point upwardly. Consequently when no current is flowing the cores of the solenoids or magnets are moved back to their normal positions by the force of gravitation. The position of the device when set up is illustrated in Fig. 1, the pivot d being the lower part of the device. I prefer to use gravity in place of a spring, because of the usual advantages and because the core will be drawn into the solenoid as if by a hammer-blow, or practically instantly. The effeet is to release or unlock the cores of the solenoids much more quickly than if retractile springs were employed. All this is true, especially with regard to the magnet or solenoid f, whose core by a hammer-blow strikes the weight '17 and unlocks the teeth 20 practically instantly.

One of the advantages connected with the device is its adaptability to be a self-protection from careless or ignorant handling when starting. In starting, the handle-lever b is turned to the position of the lever a, and then the core of the magnet 6 may be pulled inwardly against the action of gravity by the operators finger. Now both levers are turned to the right. As soon as the first contact is reached in the row of contactsj the finger is removed and the current in the shunt-magnet 6 holds the levers together. If now at any contact the current in the series magnet f is abnormally strong, the lever a will immediately return to its normal position for reasons heretofore stated. Sometimes, again,

the motorman, especially if careless or a new hand, may cut out the resistance too fast,caus- 1. In an electric-motor-starting rheostat= switch, the combination of two levers, the one carrying an operating-handle and the other carrying the contact-pieces for the rheostat, and the levers being locked together and electromagnets adapted to lock and unlock said levers from each other.

2. In an electric-motor-starting rheostatswitch the combination of two levers, a de vice for lockin g and releasing said levers from each other, a magnet on one of the levers in a given main line, a magnet on the other lever in a given shunt-circuit and each magnet controlling the lock and releasing device.

3. In an electric-motor-starting rheostatswitch the combination of a lever carrying a magnetin circuit with and electrically connecting the contacts of the rheostat, a device for holding the said magnet in a position to be in circuit with any desired number of the resistance-coils, and means,controlled by said magnet for releasing said lever from said device.

4. In an electric-motor-starting rheostatswitch, the combination of a lever carrying a magnet in circuit with and electrically connecting the contacts of the rheostat, a device for holding the said magnet in a position to be in circuit with any desired number of the resistance-coils, and means controlled by said magnet for releasing said lever from said device consisting of a handle carrying a core for said magnet which is adapted to be locked to and released from the core of the first-named magnet.

Signed this 2d day of January, 1899.

EDIVIN H. PORTER.

Vitnesses:

HARVEY E. CRANE, H. G. KEEGAN. 

